The present invention relates to a slide fastener or a zip fastener with an end stop. Whilst the present invention finds particular application for use with slide fasteners having coupling elements, it can be used with fasteners having metallic coupling elements which are crimped in place on the fastener tape edges, but is preferably used with moulded or formed elements. The slide fastener and the end stop of the present invention is more preferably used with plastics coupling elements.
One of the rare drawbacks of using modern day slide fasteners or zip fasteners is that the chain formed by the interdigitation of the couplings elements on almost any slide fasteners can be broken by folding the slide fastener back on itself and applying enough pressure or, pushing on the interlocking coupling elements with enough force so that the interdigitation or coupling of the coupling elements is broken. In most cases this is a very rare event but when it does occur for example by the use of excessive force, the product into which the slide fastener has been attached will in effect become useless.
One method which is often employed to restore the slide fastener broken in this manner is to try and force a slider present on the slide fastener over the coupling elements which have been forced open, to the start position of the slide fastener, and then pull the slider up again in an attempt to force the erroneously opened coupling elements into a cooperating arrangement again. On an open ended slide fastener (that is, a slide fastener wherein the two tapes are joined together by using a separable bottom stop), this is a relatively straight forward procedure because the slider can be returned to the start position. For a closed end slide fastener (this is where the bottom end of the chain has joined tapes) the slider can be returned to the start position at the bottom of the slide fastener but this approach is not sufficient. The reason for this is that when using a slide fastener the coupling elements need to pass around the diamond present in the centre of the slider in order to be presented at the correct angle for closure. Therefore, a diamond of the slider needs to start from a position below the open coupling elements.
However, the diamond can never move below the rear portion of the slider because it is fixed towards the front portion of the slider. Further, in a closed end slide fastener, the bottom of the slider can never go below the bottom stop because if it did so the slider would fall off the slide fastener. As a result, even when the slider is at the bottom of the slide fastener there will always be coupling elements which will remain separated once the chain has burst thereby preventing the complete re-closure of all of the coupling elements on the slide fastener. This situation is obviously unsatisfactory for slide fasteners used in a range of applications. The present invention therefore seeks to address this problem, by means of an improved end stop, most preferably an improved bottom end stop.
Whilst not limited thereto, one situation where the present invention is particularly useful is with slide fasteners having a thermoplastics coating layer such as some concealed fasteners or with fluid tight slide fasteners as described in EP-A-1057423 and EP-A-1175842. In these arrangements, the natural or synthetic rubber of thermoplastic coating layers or waterproof layers applied on one surface of the fastener tapes abut one another above the plane of the coupling elements to form a seal which prevents infiltration of water. Consequently, for fasteners with thermoplastics coating layers creating watertight seals as described above, the problem of fasteners with coupling elements which are forced apart renders the articles into which the slide fastener has been applied useless.
The present invention therefore also seeks to overcome any problems associated with waterproof slide fasteners for the slide fasteners with closed end stop, in which the coupling elements have become disengaged. However, the present invention primarily seeks to address the problem of slide fasteners in which some or all of the coupling elements have burst open and it is desired to re-interdigitate all of the coupling coupling elements in the slide fastener.
Various methods exist for forming closed end stops on slide fasteners. Closed end stops are end stops which bridge the fastener tapes to secure the two tapes together as well as arrest the travel of the slider. Most often a closed end stop is used at the bottom end (a lower side) of a fastener, but there are occasions when such an end stop is also used at the top end in a slide fastener in which one or more sliders are used. However, the aim of the bottom end stop (or top end) is to prevent a slider from coming off the slide fastener when t slider is reciprocally moved thereon to open and close the coupling elements and hence the slide fastener.
Typically a most basic end stop is formed by crimping a metal staple or crimp on to the fastener tapes or tapes. For a bottom end stop, the metal staple or crimp may be provided to bridge the two tapes of the slide fastener to hold them together and thereby prevent a slider present from coming off the slide fastener.
In EP 1,964,486 there is disclosed an end stop for use with waterproof slide fasteners comprising a pair of tapes and coupling elements along adjacent edges of the tapes wherein the tapes are partly cut away to form a gap into which an end stop is moulded and which extends along the tape edges and away from the coupling elements.
In U.S. Pat. No. 3,924,305, strips (pieces of fabric) are fastened across the end of the fastener chain, below the closed bottom end stop, to provide reinforcement and in JP-UM-63-28887 an end stop is formed by welding a strip on to a group of coil type coupling elements.
With continuous coil type coupling elements, there have been many attempts to utilise the coupling elements themselves to form an end stop. These attempts have typically involved melting the coupling elements, such as described in GB-A-1270179 to fuse opposed coupling elements in coupled disposition (for a bottom end stop) or to fuse adjacent coupling elements at their upper ends on a tape edge (to form a top end stop). However, this approach has typically resulted in unsatisfaction for the end stop or the coil-shaped coupling elements because it is elaborate or time consuming processes.
In U.S. Pat. No. 4,091,509 there is described a slide fastener with a bottom end stop in which an elongated member is inserted through the coinciding central openings of interlocking coils at the bottom of the slide fastener and which is then secured in place by deforming one or more of the convolutions of the coils at the bottom of the slide fastener.
In EP 1,543,739 there is described an end stop for a slide fastener which includes a rod-like body and coupling heads of coupling elements, both of which are comprised of synthetic resin. The slide fastener is formed by selectively fusing together the rod-like body and the coupling heads of the coupling elements on the slide fastener once the rod-like body has been inserted into the space created by the coupling heads.
In GB 1,024,733, EP 1,772,071, EP 0,345,799, EP 1321062, and U.S. Pat. No. 3,616,939 there are again disclosed various forms of slide fasteners with end stops in combination with water proofing properties, however, none of these documents address the problem of the present invention which provides an end stop for a slide fastener in which the bottom couplings elements are so joined to ensure that there can never be any coupling elements which may remain disengaged even when the chain of the slide fastener has been broken.